Mixture compressing internal combustion engine with fuel injection



July 14, 1959 K NALLINGE F. H MIXTURE CO ESSING INTERNAL WITH FUEL ENGI INJECT Filed March 14, 1957 FIG. 2

COMBUSTION ION FRIEDRICH K. H. NALLINGER INVENTOR ATTORNEYS Unite States Patent MIXTURE COMPRESSING INTERNAL COMBUS- TION ENGINE WITH FUEL INJECTION Friedrich K. H. Nallinger, Stuttgart, Germany, assignor to Daimler-Benz Aktiengesellschaft, Stuttgart-Unterturkheim, Germany Application March 14, 1957, Serial No. 646,092

Claims priority, application Germany March 15, 1956 9 Claims. (Cl. 123-439) The present invention relates to a motor vehicle and more particularly to the control arrangement of a mixtum-compressing internal combustion engine having fuel injection in which a retarding or delay mechanism is inserted in between the throttle valve in the inlet manifold and the actuating device simultaneously controlling the amount of fuel injected into the cylinders.

The operation of motor vehicles is characterized by recurring changes between acceleration and deceleration of a motor vehicle and, in that respect, is in sharp con trast to the operating conditions with rail vehicles, ships, and airborne vehicles of any type. For purposes of acceleration a rapidly responsive increase in output of the motor vehicle driving engine is necessary. It is, therefore, necessary that as soon as the driver, by actuating the output control member of the motor vehicle, has given the command for acceleration of the vehicle the prerequisite for an increase in the engine output be established as rapidly as possible.

In the operation of a motor vehicle by means of a fuel-injection internal combustion engine of the mixturecompressing type, this means that as rapidly as possible an adjustment for an increased injection quantity be established and such increased quantity be supplied to the internal combustion engine. Furthermore, during the acceleration not only a larger absolute injection quantity but also a more rich mixture, i.e., a larger value of the ratio of fuel to air in comparison to the economic normal operation is advantageous for the instantaneous large output requirement. The mixture adjustment for normal operation may then Well be selected somewhat more economically as long as, for purposes of acceleration, the rich mixture providing a sufficiently large output is available.

During deceleration, i.e., upon taking the foot off the gas pedal, it is also desirable that there be an instantaneous decrease in the injected fuel quantity as otherwise the deceleration of the vehicle is retarded and as any further injection of the fuel in the pro-existing amount becomes unnecessary and useless during deceleration. Under certain circumstances, it may also be advantageous if upon release of the gas pedal a predetermined lack of fuel is present in the mixture. In that case, a super-enrichment of the fuel mixture cannot take place under any circumstances and therewith the prevention of the formation of unpleasantly smelling exhaust gasses or fumes is assured. Furthermore, a certain amount of fuel may be saved in the operation of the vehicle.

In recognition of these considerations, the present invention proposes for motor vehicles driven by means of a mixture-compressing fuel-injection internal combustion engine that the actuating member which determines the driving output of the motor vehicle, for example, the gas pedal, be positively connected, on the one hand, with the member controlling the fuel injection quantity, for example, the control rod or rack of an injection pump, and, on the other hand, be connected with the member controlling the combustion air, for example, a throttle valve, by means of a delay mechanism. In particular, the arrangement may be so made that the throttle valve is positively connected with the piston of a hydraulic damping mechanism and is connected with the gas pedal by the insertion of a spring.

Depending on the operating characteristics of the internal combustion engine or of the vehicle and on the conditions of the driving operation, it may be appropriate that by the use of a damping arrangement of known construction, which has different damping efficiencies or characteristics in the two directions of operation thereof, the lagging of the throttle valve with respect to the gas pedal may have a different value during acceleration as during deceleration. In particular, the arrangement may be made so that the damping mechanism is weaker in the direction of deceleration than in the direction of acceleration, or possibly is not effective at all in the former.

Accordingly, it is an obejct of the present invention to provide a control arrangement for mixture-compressing fuel-injection internal combustion engines which obviates the disadvantages of the prior art devices, particularly as regards the lack of proper response to command in changes of engine performance.

It is another object of the present invention to provide a control arrangement which improves the responsiveness of fuel-injection, mixture-compressing internal combustion engines.

It is still another object of the present invention to provide a delay mechanism between the output control element and the throttle valve controlling the combustion air of an internal combustion engine of the mixture-compressing type with fuel injection.

Still another object of the present invention is to provide a fuel-air mixture control arrangement and more particularly a control arrangement which varies the ratio of the fuel to air in a simple yet highly appropriate and effective manner so as to improve the operating characteristics of the engine and bring about saving in the fuel consumption thereof.

These and other objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the drawing which shows, for purposes of illustration only, one preferred embodiment of the present invention, and wherein:

Figure 1 shows schematically a motor vehicle provided with a control arrangement according to the present invention having an injection-type mixture-compressing internal combustion engine, while Figure 2 shows a partial cross section of a modified version of the damping mechanism shown in Figure 1.

Referring now more particularly to the drawing wherein like reference numerals designate like parts, reference numeral 1 designates the actuating member controlling the output of the engine, such as a gas pedal which is connected by a direct link 2 with the control rod or rack 3 of the injection pump 4. Supply lines (not shown) lead from the injection pump 4 to the injection nozzles of the individual cylinders of the engine, as is well known. Furthermore, the gas pedal 1 which is pivotally journalled at 5 is connected with a piston 7 over a draw or tension spring 6. The piston 7 is slidingly arranged in a cylinder 8 which is filled with a suitable hydraulic fluid, such as oil, The hydraulic fluid upon displacement of the piston 7 is forced to flow from one side of the piston to the other over a relatively narrow overflow or throttling passage 9. The piston 7, cylinder 8 and throttling passage 9 form a retardation device or delay mechanism of conventional construction, although it is understood that any other delay mechanism of suitable characteristic may be substituted therefor.

A direct linkage 10 interconnects piston 7 with lever 11 which is rigidly secured "on the shaft of the throttle v-a1ve'12: 'The'iever 11 and therewith also the piston 7 are urged toward the left, as viewed in the drawing, i.e., into the closed position of the throttle valve 12 by means of a tension spring 13'.

pe ati n When giving gas, i.e., during acceleration of the vehicle, as becomes quite clear from the drawing, the control rod 3 is displaced instantaneously upon actuation of the gas pedal 1'so that instantaneously a larger amount of fuel is Supplied to the engine from the fuel injection pump-4. However, the piston 7 is able to follow the draw or tensioning movement of the spring 6 only slowly as the'piston 7' is forced to gradually displace the oil in the cylinder 8 disposed on the right side of the piston 7 to theleftside thereof through the overflow channel 9. As a result thereof, the opening of the throttle valve 12 is delayed.

In reverse, upon releasing or taking ofi the foot resting on the gas pedal 1, the spring 6 instantaneously rotates the gas pedal counterclockwise so that the control rod 3 of the injection pump 4 is instantaneously adjusted toward the right in the direction of a smaller quantity of injected fuel. The piston 7 and therewith the throttle valve 12, however, are not brought back instantaneously by the spring 13 into a left or more throttling position of valve 12 as the oil at first has to flow from the left side of the piston 7'throughthe overflow channel 9 to ward the right side thereof.

The invention is not limited to the illustrated embodi ment. For example, instead of the oil-hydraulic damping mechanism any other suitable damping and delay mechanism may be used. Furthermore, the control rod 3 and the damping piston 7 may be arranged in series rather than in parallel as illustrated in the drawing. On the other hand, the damping mechanism may also be arranged altogether by itself, i.e., without being arranged or inserted in the linkage of the connection between the gas pedal and throttle valve but merely acting thereon, for example, controlling-a lost motion mechanism. More over, the damping mechanism may be arranged in a manner similar to shock absorbers of motor vehicles Which, as is well known, are so constructed that they are only effective in one direction, preferably providing delay in the direction of acceleration or giving gas.

Thus, it maybe seen that the present invention is susceptible of many changes and modifications within the scope of the present invention, and I intend to cover all such changes and modifications as encompassed by the appended claims.

I claim:

1. A motor vehicle driven by a mixture-compressing, injection-type internal combustion engine comprising actuating means for controlling the output of said engine, a fuel pump including adjusting means for varying the amount of fuel injected into said engine, means for controlling the quantity of combustion air supplied to Said engine, connecting means for directly connecting said actuating means with said adjusting means, and further connecting means including delay means ,for connecting said actuating means with said control means for controlling the quantity of combustion air, said delay means being efifective during acceleration as well as during deceleration of said engine.

2. A motor vehicle according to claim 1, wherein said delay means includes a piston slidingly accommo- 4 r dated in a hydraulic delay mechanism, and wherein said further connecting means connects said control means positively with said piston, on the one hand, and said actuating means with said piston by means of a spring, on the other.

3. A motor vehicle according to claim 1, wherein said delay means has different delaying characteristics in the two directions of operation thereof.

4. A control arrangement for a mixture-compressing, injection-type internal combustion engine comprising actuating means for controlling the output of said engine, a fuel pump including adjusting means for varying the amount of fuel injected into said engine, means for controlling the quantity of combustion air supplied to said engine, connecting means for directly connecting said actuating means with said adjusting means, and connecting means including delay means for connecting said actuating means with said control means, said delay means having a different degree of damping effect in the direc-.

tion of movement of said actuating means corresponding to acceleration of said engine than in the direction of deceleration thereof.

5. A control arrangement according to claim 4, where; in the damping effect of said delay means is weaker in the direction of deceleration thereof than in the direction of acceleration thereof.

6. A control arrangement according to, claim 4, wherein said delay means includes means for limiting the delaying effect thereof to a degree approaching zero during movement of said actuating means in the direction of deceleration of said engine.

7. A, motor vehicle driven by a mixture-compressing, injection-type internal combustion engine comprising a gas pedal for controlling the output of said engine, a fuel pump including a control rack for varying the amount of fuel injected into said engine by said pump, means. in.- cluding a throttle valve for, controlling the quantity of combustion air supplied tosaid engine, connectingrneans for positively connecting said gas-pedal with said-adjust ing means, and further connecting means including delay means for non-positively connecting said gas pedal: with said throttling valve, said delay. means being effective during acceleration as wellasduring deceleration of said en-v gme.

8. A motor vehicle according to claim 7, whereinsaid further connecting means includes a spring.

9. A motor vehicleaccording to claim 8, wherein said delay means is a hydraulic delay mechanism with a cylinder, a piston in said cylinder, and means for throttling the passage of the hydraulic mediumin said cylinder from one side of the piston to the other in one direction of displacement of said piston.

References Cited in the fileof this patent UNITED vSTATES PATENTS 1,429,528 Payne Sept. 19, 1922 2,074,514 Muller Mar. 23, 1937 2,104,649 Hinton Jan. 4, 1938 2,150,075 Mennesson Mar. 7,.1939 2,189,475 Saur Feb. 6, 1940 2,346,458 Sanders Apr. 11, 1944 2,731,792 Nallinger Ian. 24, 1956 2,794,432 Nystrom June 4, 1957 FOREIGN PATENTS 705,331 France June 4, 1931 458,211 Great Britain. Dec. 15, 1936 

